The present invention relates to an X-ray mask for use in an X-ray LIGA process; and, more particularly, to an X-ray mask with a micro-actuator for precisely controlling a position of the X-ray mask to generate a three-dimensional microstructure.
In recent years, an X-ray LIGA technology by an X-ray mask is widely employed to fabricate a three-dimensional microstructure.
The term xe2x80x98LIGAxe2x80x99is an acronym of German words Lithographie, Galvanoformung and Abformung which imply lithography, electroplating and molding, respectively. Therefore, the X-ray LIGA refers to a micro-fabrication technology for forming a microstructure through an X-ray lithography process, an electroplating process and a molding process.
By using the X-ray LIGA technology, a microstructure of vertical side wall with a height ranging from tens of xcexcm to several cm can be obtained. Since the roughness of the microstructure of vertical side wall is hundreds of xc3x85, the microstructure fabricated by the X-ray LIGA process is highly precise.
The X-ray mask is a device for selectively eradiating the X-ray during the X-ray lithography process. The X-ray mask is located between a photoresist film and an X-ray source.
Referring to FIG. 1, there is provided a schematic front view of a conventional X-ray mask. The conventional X-ray mask includes a thin silicon/silicon nitride membrane 1 and an Au X-ray absorber 2 formed on the membrane 1. The X-ray permeates the silicon/silicon nitride membrane 1 without experiencing any energy loss but cannot pass through a region wherein the X-ray absorber 2 is prepared. Accordingly, the shape of the X-ray absorber 2 is transferred to a PMMA (polymethylmethacrylate) substrate or the photoresist film (not shown). The membrane 1 is supported by a mask holder 3. Above the X-ray mask is located the X-ray source (not shown) while beneath the X-ray mask is prepared the PMMA substrate or the photoresist film to be exposed to the X-ray.
Though the conventional X-ray mask as described above shows a great efficiency in fabricating a simple microstructure having a vertical sidewall, a three-dimensional microstructure with a non-vertical sidewall may not be easily fabricated by using the conventional X-ray mask. In order to obtain various three-dimensional microstructure by using the conventional X-ray mask, the X-ray mask or the PMMA substrate should be circularly or horizontally moved relative to the X-ray source. Accordingly, an additional precision equipment is required and, thus, the volume and the cost of the X-ray mask may not be reduced below a certain level.
It is, therefore, an object of the present invention to provide an X-ray mask incorporating therein a micro-actuator capable of directly operating the X-ray mask.
In accordance with the present invention, there is provided an X-ray mask with a micro-actuator including:
a mask portion including a thin shuttle mass and an X-ray absorber attached on the shuttle mass;
a mask holder portion formed around the mask portion with a predetermined distance maintained therebetween;
at least one elasticized supporter for elastically connecting the mask portion and the mask holder portion; and
a micro-actuator unit prepared between the mask portion and the mask holder portion for precisely controlling a position of the mask portion when a voltage is applied.